Nearly 1 in 3 teens has sent a nude picture of him or herself to someone else, and more than half have been asked to do so, according to new research on nearly 1,000 Texas teens. The study, published Monday in the Archives of Pediatrics and Adolescent Medicine, also found that teen “sexting” is strongly linked to actual sexual behavior.

About 77% of girls aged 14 to 19 who had sent a sext reported having had intercourse, compared with 42% of those who hadn’t sexted. For boys, 82% of those who had sexted had had sex, while 46% of non-sexters had done so. The study included teens in the 10th and 11th grades, with an average age of about 16 (the overall age range spanned 14 to 19).

The new research suggests that sexting is far more common than past data have indicated. For example, one previous national study of more than 1,500 youth, published in the journal Pediatrics, found that just 1% of children and teens had sent a sext and 7% had received one. The authors of the new study, led by Jeff Temple of the University of Texas Medical Branch, take issue with the sampling of that data, however, noting that it included mainly white teens from two-parent families and many with higher-than-average incomes.

In contrast, the teens included in Temple’s study, recruited from seven public schools, were relatively evenly split between black, white and Hispanic students, with smaller percentages of Asians and mixed-race teens. But a co-author of the Pediatrics paper, David Finkelhor, director of the Crimes Against Children Research Center at the University of New Hampshire, finds the sampling in the newer research problematic as well. “The [authors] don’t describe how the schools were chosen and there’s no analysis of nonresponse,” says Finkelhor, noting that since parental permission was required for participation in the current study, those whose parents said no and were excluded might have been less likely to sext.

However, the new research does conform with earlier studies in another way, suggesting that sexts are generally not sent casually. They are typically intended to be viewed only by an intimate partner with whom the teen already has or wants to start an ongoing relationship. Whether or not the images are actually kept private depends on the trustworthiness of that partner, of course, and more importantly, on their impulse control — a trait that is not usually at its strongest during adolescence.

The study found a few differences by gender: while girls and boys were equally likely to send nude images, boys were more likely to ask for one and girls were more than twice as likely to report having been asked. Girls were far more likely to say they were “bothered” by such requests, however: more than 90% were at least somewhat bothered, with a majority being bothered “a lot” or “a great deal”; nearly half of boys said that being asked for a nude photo didn’t bother them at all.

For girls, sexting was also linked with risky sexual behavior: more than half (56%) of those who’d sent a sext had had more than one sexual partner in the previous year, compared with 35% who had not sexted. Using alcohol or other drugs before sex was also more common in female sexters than non-sexters: 40% versus 27%. Among boys, only those who had been asked to send a sext were more likely to show risky sexual behaviors.

The authors theorize that these gender differences are linked to the good old double standard that characterizes sexual behavior by males as admirable and acceptable, while scorning the same activity in females. They write:

It is possible that sexting, like actual sexual behaviors, is perceived more permissibly and positively for boys…and therefore less likely to be associated with other risky behaviors. Girls, on the other hand, may risk being stigmatized for their sexting behaviors (e.g., being identified as a “slut”).

Sexting itself does carry legal risks. Even self-created images of teens are considered child pornography by law, if they are sexual in nature, and can lead to prosecution, incarceration and lifetime inclusion on sex offender registries. “The ubiquity of sexting supports recent efforts to soften the penalties of this behavior. Under most existing laws, if our findings were extrapolated nationally, several million teens could be prosecuted for child pornography,” the authors write.

Further, they note: “In an adolescent period characterized by identity development and formation, sexting should not be considered equivalent to childhood sexual assault, molestation and date rape. Doing so not only unjustly punishes youthful indiscretions, but minimizes the severity and seriousness of true sexual assault against minors.”

Our legal system criminalizes behavior that is “normal” for many teens, says psychologist Christopher Ryan, author of the bestselling Sex at Dawn, which looks at the prehistoric origins of human sexuality. “We shouldn’t panic about the fact that kids are sexual beings. We should adopt an approach based upon the Dutch understanding that we must ‘tolerate in order to control,'” he says. “Kids will be kids, whether they’re playing doctor, spin the bottle or sexting. It’s the adults and our legal institutions that have to grow up already.”

But the worst fears about prosecution may have been overblown. In another Pediatricsstudy published in December, Finkelhor and his colleagues found that nearly 3,500 cases of sexual images produced by teens came to the attention of law enforcement agencies in the U.S. between 2008 and 2009. Two-thirds of these cases, however, had “aggravating” factors — such as involvement of an adult or use of the images by a teen to harass, bully or intimidate the victim. Teens were arrested in 18% of cases where there was no aggravating factor, and registration as a sex offender occurred in only 10 cases, nine of which involved actual sexual assault, not just the sending of images. In the tenth case, which involved a boy who sent a picture of his penis to a peer, the perpetrator had an extensive criminal history.

The research also found that the majority of the images involved in these cases — two-thirds — had been distributed by cell phone, not over the computer. However, that means one-third were posted somewhere on the Internet.

Finkelhor cautions against making too much of the new stats on sexting. “I just like to point out to people that if you look at the global measures of teen sexual behavior, all of them are moving in the direction we’d like to see: teen pregnancy is down, the number of teens with multiple sex partners is down, the percent who have ever had sexual intercourse has been declining, and the percent of teens who use contraception has been going up,” he says, adding, “I don’t think people should be complacent, but I don’t think that sexting or the Internet is looking like it’s provoking some drastic worsening of sexual risk behavior.”

The new research also suggests that pediatricians discuss sexting with their teen patients. Although no parent wants to imagine their child engaged in sexting, the authors argue that there may be a clinical benefit for doctors to talk about it:

Asking about sexting could provide insight into whether a teen is likely engaging in other sexual behaviors for boys and girls, or risky sexual behaviors for girls. … [Q]uestions about sexting may be easier for teens to answer honestly than questions about sex and risky sex behaviors.

The authors encourage pediatricians to use the issue to start a discussion about safer sex, concluding that it is “essential that pediatricians, adolescent medicine specialists and other health care providers become familiar with, routinely ask about and know how to respond to teen sexting.”